Posts about: "AAIB (All)" [Posts: 151 Pages: 8]

This aircraft has got airborne well within the requirements of FAR 25 under which it was certified. It has over 1250m ahead of it passing around 35' based on the video from behind, so the FMC data was not incorrect, the thrust up until after TO was not incorrect, and the CG is not out of range, the time to rotate is within expected range, and the attitude at liftoff is not excessive, the plane is not heavier than expected. This is not Emirates, Tiger or SQ, it may have a resemblance to AFR out of Nigeria, or ANZ out of Raro, or UAL out of Hilo. Unlikely but there are similarities.

A low altitude in the MCP can become pretty interesting, as will a TAT probe failure to the ATR thrust limit. Both cases will have the thrust levers moving back rapidly. There is no obvious failure of the engines at this point save the question that the RAT may be deployed. A transient electrical fault tripping the logic for the RAT is hard to imagine, but that would possibly end up with an ATR fault and power coming back to idle. Fuel contamination is not impossible, but it is improbable, the engines would have been on their TO configuration from the engine start, and the taxi and turnaround takes enough time to flush the fuel lines, being longer than the selected tank sampling time that sits behind the SOPs. Boeing aircraft are easier for the crew to detect anomalous thrust commands compared to the Airbus, however, if the RAT is out... then more was happening.

The flaps are in the correct position, we are looking at a time critical failure for the crew, they appear to have around 10 seconds between onset and impact, and they have rotated the aircraft in the later stages, as any reasonable pilot would do, and that certainly does not indicate a crew initiated problem on the available information. Unlawful interference is unlikely, given the RT calls that have been made.

The IDGA AAIB is not known for rapid response, this event is of international importance, it appears that it is being treated as such by the authorities involved. The EAFRs on the 787 will tell all soon, and we need that information, this is a globally important aircraft type.



It said on the TV that people.from.the UK AAIB are going out to help

I think the word you are looking for is "inconceivable".

AFAIK , both the NTSB and UK AAIB are by now onsite to assist the investigation at the request of the Indian AIB. The suggestion that they wouldn't notice, or would be party to, funny business with the flight recorders is ridiculous.

I believe and hope you're right, Dave. But don't be so quick to eliminate unorthodox business. India's a funny old country.

It's tempting to think that, however one may also have made the case 'why doesn't Boeing install a system that prevents the nose getting too high on the 737 MAX? Then they won't have to retrain crews on handling differences'. We know how that worked out.

When designing anything you need to account for unintended consequences and the possibilities for that system adversely affecting safety if it were to malfunction. If you introduced a system designed to prevent flap retraction 20 to 30s after liftoff, what if failure in a channel of that system then prevents flap retraction required to achieve a MACG with critical terrain on departure. We could 'why don't they do this / why don't they do that' until eventually we end up with not flying at all.

On your point of integrated scales, there is a far easier way to cross check actual aicraft weight with calculated weight: a computer that cross references acceleration data on the takeoff run with known values from lookup tables based on specific environmental conditions and engine thrust settings. If you're not accelerating at a normal rate expected for the calculated thrust and weight a warning can be triggered. This was a recommendation echoed by the AAIB following the incident with a Jet2 aircraft getting airborne at only 70% thrust. I believe Airbus and Boeing are looking into the potential implementation of such a safety system.

This I believe is an option to retrofit. Can\x92t recall the supplier, Honeywell perhaps, not sure on the 737-MAX and whether it has anything fitted as standard.. Anyway the more cost effective option (for NG operators) is to amend SOPs where appropriate. However the U.K. CAA do apparently intend on creating a working group regarding such events. See also the TUI event at BRS.

https://asn.flightsafety.org/wikibase/388602

https://simpleflying.com/aaib-report...f-runway-10ft/

It\x92s worth noting that the acceleration rate was exceptionally low in the TUI event based on the average for that airport. I refer you to my initial post on this thread, it\x92s a risk that there is no config warning horn (to my knowledge) on the B737-800 that will alert the crew, upon selection of TOGA, that the performance solution entered into the FMC does not agree with the actual config. In the case of flap setting, it will only alert if a non standard take-off flap setting is selected. If in the unlikely event TOGA is not pressed at all then\x85..

Airbus have added something of an FWC to their 321NEO aircraft that will alert crew to this - something I\x92d heard from bus mates but wasn\x92t 100% certain on so thanks to those on here that confirmed.

Sorry for further thread derailment, however felt it might be of interest. 787 rated crew on this thread suggest this would form part of the electronic checklist on the aircraft so in the case of the event at hand a red herring.

I read that the 'AAIB' will be investigating. I presume that's AAIB (India)? Do we know what facilities the AAIB (India) has for reading FDRs?

reported were India AAIB with support from NTSB, earlier report was about UK AAIB ref the 50 plus UK passengers, other report mentioned Boeing and GE supporting.

On the day of the crash BBC news reportes a number of British AAIB members were flying out to India

from the EASA statement yesterday :
​​​​​​​No mention of UK

AAIB (UK) Update: Air India flight AI171

The point you think you are making here has recurred throughout the thread. To try and put it to rest:

The first omission/error here is in describing a definite article (i.e. the video), alongside claiming that the pic you posted is 'unprocessed". It might not be processed, it just isn't very good quality. Which you might not realise if you haven't seen the original, higher resolution version of the clip.

The are now numerous social media sources for copies of the flyby/crash smartphone video. Many of them are actually a repost (or possibly multiple independently made iterations) of a second generation recording - made via a smartphone filming the original video playing on a monitor and via the monitor's (likely very poor) speakers. This version has been incorrectly assumed to be (and described as derived from) "CCTV" in some posts. The "screen recorded" nature of this particular version of the video is obvious from the camera movement (including showing the bezel and edge of the screen it is filming), moire patterns etc. The original (or rather, what *appears* to be a first generation, but compressed, copy of the original) version of the video has *also* been posted on social media (and thereafter, here) with both then being dissemanated across multiple social media accounts and at varying video resolution and compression ratios.

There are further posts of the "screen recorded" copy of the video in which AI enhancement and other filters have been used to try and "improve" the video quality. Anyone even attempting to filter the video in that way doesn't understand the way such filters operate (i.e. they are trying to make the picture "more watchable" rather than sharpen it/make it more *accurate*), and anyone trying to draw conclusions from such "enhanced" versions needs to think carefully about what they are looking at.

The framegrab you have posted above is clearly from the "screen recorded" video. The original version (with its attendant much higher video *and* audio quality) *does* appear to show an object beneath the airframe where the RAT hub would be - and also - albeit only for a handful of frames - appears to show the motion blurred impeller disc. The fact that this artifact is only visible for a few frames is explicable via the heavily compressed digital video but it is consistent.

The "full" video itself is also longer than the "screen recorded" version and starts earlier in the incident timeline. And a distinctive propeller-type beat *is* audible, both before *and* after the aircraft comes into frame, at near identical pitch to the various examples we've seen of a 787 passing a camera with the turbine deployed. One would imagine that the first generation copy of the video as it exists on the device that recorded it is noticeably better quality than *any* of the downsampled/overcompressed social media versions we have seen. And one also sincerely hopes that the Indian AAIB are already in possession of it.

The prevalence of smartphones and social media means this sort of footage is more immediately accessible and more easily dissemanated than at any time in the past. However, anyone trying to draw solid conclusions from a clip posted on social media - especiallly with limited quality, and even more, "enhancement", needs to remember the limitations of what they're seeing.

(Not a pilot, but a former aero electronics engineer with significant subsequent digital forensic experience)

Re FDR and CVR, remember the 787 uses EAFR(s) instead - one in tail and one in nose.

Comments above "they will already have been read" - suggest search and read India press links, and the (new) India AAIB lab ability to read data recorders, e.g. one timed at June 15, 2025 00:08 IST. It may well be the first 'political' issue about this accident in where the recorders are sent. If India is chosen, maybe they will take their time with a new lab, and watched over by the world and other AIB representatives? I believe the investigating state 'controls the release of information' (or not). Whilst the UK AAIB are there, as their website says they have 'expert' status, which I suspect means not a lot of involvement in the politics.

Dont be afraid. I am following along. There is no evidence. Can you vouch for the authenticity of the audio recording? I cannot see a RAT in that image only a blur.

I tell you what I am watching closely, the words and subtle meaning in the press conference of Civil Aviation Minister, Shri Ram Mohan Naidu, who has set up a “special high level committee” to oversee the investigation of this “incident.

A little odd given they have the DGCA and AAIB in place, dont you think?

He indicates they are to report within three months.

It is now 48 hours since the EAFR was recovered. A small group of people know the answer NOW.

The investigation is being led by the AAIB of India, not Boeing or US regulators. While the investigators will be mindful of a wide range of industry-related issues, I doubt they have any concern for what may or may not be 'consequrences to the USA's national security'. If there is any politics involved in obfuscating and delaying the investigation, they'll be Indian politics surely?

This is assuming too much. There are legal and technical reasons why the CVR may not have been downloaded yet or, if it has, why no information has been released.

In an ICAO Annex 13 investigation, interested states and experts are invited to participate. In this investigation, investigators from the US and UK are participating (there may be others as well), and experts from Boeing (and possibly component manufacturers) have also been invited. The lead investigators will often hold off on recovering data from the CVR and FDR, or examining the data, until there's agreement between the interested parties on how to go about doing it. With the distances involved, travel logistics could easily delay examining the data by a couple of days.

In some cases, the board leading the investigation doesn't have the internal expertise to recover data from the CVR and FDR. In these cases, agreement needs to be reached on which technical experts are going to take the lead on recovery. I don't know if the Indian AAIB has internal expertise or if they need to find external expertise to recover the data.

In some cases the CVR and FDR can be damaged and technical experts need time to come up with a plan to repair the recorders and recover the data.

Annex 13, Article 5.12 prohibits the release of CVRs and analysis/opinions from FDRs, unless the investigators decide that the benefits of the disclosure would outweigh the adverse impact that release would have on future investigations. This rule exists to encourage full cooperation in investigations from participants in the industry, including pilots and operators. India's accident investigation rules are consistent with Annex 13: see section 17 of the Aircraft Investigation of Accidents and Incidents Rules, 2017. So even if the CVR and FDR have been analyzed, it may well be that information isn't being disclosed to the public because they haven't reached any definitive conclusions yet that they're confident will end up in the final report.

https://www.gov.uk/government/news/a...a-flight-ai171

UK AAIB Link here for updates

MR120

There won't be updates from the UK AAIB.

" In accordance with international protocols, release of information on the investigation rests solely with the Indian authorities. "

I would guess that 787 pilot seats are electrically moved and use a worm gear drive.

I'd be surprised if they are mechanically adjusted and held in place by a pin.

If there was a loss of power, it happened after V1. Normally, at V1, all hands should be removed from the thrust levers until, type dependent, selection of climb thrust, which normally takes place not below 1000\xb4 above aerodrome level. An altitude the flight never managed to achieve. If some flight crew members seat was to slide back unintentionally, there are handles in the flight deck that one will instinctively reach for, no need to grab the thrust levers of all things.

Even if the levers may have been inadvertently pulled to idle, it would have taken one single energic adjustment to slam them to maximum thrust position (whatever it is called on the 787), for which there was some time during the brief flight. And two idling engines should not result in anything triggering the RAT release or APU auto start.

Of course, stranger things have happened, but I\xb4d consider this scenario not plausible.